Method of coating



Oct. 6, 1931. w. H. CHARCH ET AL METHOD OF COATING Original Filed Oct.12, 1928 3 Sheets-Sheet 1 NTORS 2 ATTORNEY Oct. 6, 1931. w. H. CHARCH ETAL 1,826,698

METHOD OF COATING Original Filed Oct. 12, 1928 5 Sheets-Sheet 2 (71 s I.Q

MM Mkwmflwoas ATTORNEY 00L 1931- w. H. CHARCH ET AL 1,326,693

METHOD OF comma Original Filed 12. 1928 3 Sheets-Sheet 5 ATTORNEY I wereSam-.5; PATENT jorricu WILLIAM E. cinema, or soprano, mi) women a.onerous, or KENMORE, NEW roax, muons in on tour cunmrmnn comranr, we; ornew 203:, n.1,

A CORPORATION OF DELAWARE METHOD OF COATING orlginalepplloation filedllotober is, we, .Serlal Io. 312,041, and in. army October "a, 1-1:

Divided and this application filed June 18, 1980. Serial No. 461,892.

This invention relates to coating and more particularly to a method forcoating films, webs or sheets of regenerated cellulose sold under thetrade name Cellophane with a moistureproofing composition preferablycomprising a cellulose derivative, a wax. preferably parafin wax, a gumor resin, a plasticizer and a solvent or solvent mixture,

and is a division of application SerialI'No.

312.041, filed October 12, 1928.

Cellophane produced in the usual casting machine lies a head on eachedge which is two to four times thicker than the center parts of thefilm. in the usual methods of coating other materials, it was impossibleto coat a cellophane? film, sheet or web without having a large excessofcoating material on the edges or the film and ak zone about sixtheight inches in width adjacent said edges?v In order to obtain a.uniformly coated"i:ellophane film, web or sheet by these processes itwas necessary to cut away or-tiiiii the'bead prior to coating.

we have found that we can: eliminate and overcome this disadvantage andsecure a substantially uniform coated surface by wiping or removing theexcess coatingmaterial at the marginal zones adjacent the beads rior toremoving the excess coatin -material rom the entire width of the colophane film, web or sheet.

' We have found that by raising the tem erature of the coatingcomposition on the ass as rapidly as possible to approximately the sameor higher than the melting pointof the wax in the composition andmaintaining the applied coating composition in a homogeneous'state unt1lall the solvent is eliminated,

acc dental blushing can be prevented.

' When cellophane is heated, it has a tendency to losesome of itsmoisture and become somewhat brittle. This also occurs when cellophaneis coated with a moisture} proofing compositmn as herein used andsubsequently dried by evaporatin t n- I moving the doctor blades apart,permitting or solvent mixture in a heated atmosphere.

,We have found that we can'overcome this ing parts.

the coated material is subjected to a humidifying'maction the last traceof the solvent will aiso eliminated and the coated filmsubstant1alldeodorized.

It. is t erefore an object of this invention 5 to provide a method ofmoistureproofing cellophane films, webs or sheets .With a"moistureprooiing coatin composition pref? erably comprising a col ulosederivative, a

wax, such as parafin, a gum or resin, a plasticizer and a solvent orsolvent mixture to produceia substantially transparent, odor less,flexible, non-tacky material,

- Another object of this invention is to pro{ fee vide a'inetho'dwherein the wax ingredient is prevented from precipitating out dproducing a blush;

Another object of this invention'is; to prov1de a method for providing asubstantially uniform coated surface on cellophane having beadededgeswithout removing said beaded edges,

A still further object of this invention is to provide a method whereinthe'fiexibility of the coated article, which may have been lost duringthe process, is restored.

Further objects will appear from the following descriptiomappendedclaims and ad companying drawings illustrating one form of apparatuscapable of carrying out the method and in which:

Figure 1 is a front elevation of the apparatus for carrying out thisinvention.

-.. Figure 2 illustrates the, arrangement of the doctor blade mechanismand accompany- Fi2gure 3 is a vertical section through Fig- Figure 4 isavertical section taken on line 4'4 of Figure 3 illustrating thearrangement of the doctor blades.

.. Figure 5} illustrates the casting on which the blade holder trunnionsand clamps are mounted.

Figure 6 isfa; detail of: the mechanism for the machine to be'threadedwith the cello-' phane film, web or sheet.

humidifying sented to the cellophane,

' room temperature, wherebythe flexibility of the coated film isincreased and the last traces of solvents eliminated, thus rendering thecoated film odorless.

Referrin now to the drawings and especially to igure 1, where there isdisclosed one modification of a complete apparatus for carrying out thisinventlon mounted on a suitable framework, the web or film of cellophaneas it is withdrawn from a roll 1 is passed through a humidifying box 2,thence across various spreader rolls .3 and into the coating bath 4.From the coating bath 4 the film is drawn up between a wiping mechanism5 whereby the excess coating material 'is removed and thence immediatelyinto a drying or evaporating chamber 6. After travehng through thedrying chamber, the substantially dried coated film is drawn through ahumidifying chamber 7 in which there are disposed deodorizers 8. Uponthe exit of the treated film from the humidifier 7 it passes through theair and it is wound up on a roll 9. a

The roll 1 consists of a continuous film or web of cellophane as it isproduced in the usual casting machine. In other words the film or web ofcellophane has the usual beaded ed es. 1

From t e source of supply the cellophane passes through ahumidifier.Various means may be used to. humidity the cellohane. The description ofthe followlng umidifier is merely illustrative and not limitative of theinvention.

The humidifyi'ngbox 2 is made of metal and is mounted on the frameworkin any suitable position between the supply'roll and the coatingmechanism 4. It comprises a cylindrical portion 10 provided with an extension 11. In the cylindrical portion 10 there is a slot 12 providingan entrance through whichthe cellophane passes into the interior of thehumidifying box. The edges of the slot are preferably rounded to formand, damage to the latter is eliminated. The extension 11 is also formedwith a slot 13 having beaded or turned edges as described, wherebythehumidified cellophane passes from the humidifier. Mounted on thecylindrical portion 10 of the humidifier is aroll 14 which,"

together with-roll 3, provides means for guiding the cellophane throughthe humidifier.

in the sides of the extension 11 oft beads whereby smooth edges arepre-.

Connected-to or cooperating (with opleningslt e box are two ducts 17which supply the'humidifying atmosphere fromv any suitable source. Theducts may be made to terminate at the openin or they may extend intotheinterior of the box. If the latter structure is used, the portions ofthe ducts extending within thebox have their ends closed and providedwith a slot or perforation through which the humidifying atmosphere maybe introduced into the box. The amount of humidifying atmosphereintroduced is maintained by a damper 18 placed in the duct andcontrolled by a handle 19. The top of the humidifying box is providedwith movable or slidable covers or lids (not shown) whereby access tothe interior of the .humidifying boxmay be readily had. In the bottom ofthe cylindrical portion 10 of the humidifier are drip connections a orvalves 21 whereby the drippings' produced duringthe operations may beremoved. The passage of the filmthrough the humidifier isof relativelyshort duration and its moisture content is somewhat increased. The in-'crease in moisture serves to minimize to a certain degree the drying outof the film as it passes up through the drying chamber. This step aloneis usually not sufiicient to: prevent an undesirable drying out ofthefilm but in combination with the final humidifyingstep describedbelow it has been found to be effective. This humidifying step alsotends to eliminate wrinkles fromthe film and prevents a lapping over ofthe film as it passes through the doctor blades with consequent breakagewhich would ensue.

From the humidifier the film is'passedbeneath and under variousspreadingrolls 22 and 23 mounted on the frame and thence into the coating bath 4.If desired,'prior to the passageof the humidified film intothe bath,

the film may be passed through a slot'24 ad-- 7 acent which is a wiper25, which removes any drippings or globules of condensed moisture.

Submerged in the coating bath 4 contained in any suitable receptacle 26is a roller 27 threading of the cellophane through the machine. A jacket28 surrounds the receptacle whereby the coating composition may beheated or cooled by the circulatior of steam, cold air or water asdesired. To obtain optimum results the temperature of the coatingcomposition should be maintained between approximately 20? C. and 40C.Above 40 which is adapted to be raised to allow the f C. an appreciableamount of solvent evaporates, causing an undesirable atmosphere.However, a slightly'elevated temperature of the bath is preferable,because it prevents any tendency-of the wax to separate out from thecoating solution. Again, it results in a slight preheating of the film,thereby lessenmg the burden of the drier during the initial stage of theevaporation The coated. film as it emerges from the coating bath passes.through the wiping mechanism whereby the excess coating material isremoved. I 4

The wiping mechanism 5 comprises means for wiping both sides of thecellophane ,sheet, film or web passing therebetween.

Since the wiping elements for wipingthe two sides are duplicates, onlyone will be described.

The wiping m'echanism 5 comprises doctor castings 34 by any'suitablemeans. If desired, the ca s 35 may be provided with oil holes 37 w erebythe trunnions may be lubricated.

The blade carriers 31 in their lower portions have bores 38therethrough, whereby the carriers 31 are mounted on the trunnions 32.The upper extremities of the carriers 31 are formed to provide supports39 for the main doctor blades 29 which are secured thereto by bolts 40.The rear edges .of the doctor blades 29 engage shoulders 41 throughwhich'screws 42, spaced at suitable intervals in the shoulders 41, pass.The ends of screws 42 are adapted to engage the rear faces of the doctorblades 29, whereby adjustment of the Screws willadjust the doctorblades. 1

Situated beneath the main doctor blades 29 are the auxiliary or shortdoctor blades 30 mounted as immediately hereafter described. Secured toribs 43 of the blade carriers 31, and adjacent each end thereof by meansof bolts 44, are two spaced-apart elements 45. A plate 46 having a slotor hole 4'? extending at an angle, i. e. 45 to said plate, is mounted onelements 45 forming an inclined carrier 46 for the auxiliary blades 39.The carrier 46 position. 7

is provided with a plurality of' holes 48 through which screws 49 areadapted to pass. The auxiliary blades 30 are provided with slots 50through which the screws 49 pass and which ermit sufficient movement ofthe blades or accurate adjustment. By means of the nuts 49' engaging theends of the screws .49, the auxiliary blades 30 are locked in The maindoctor blades 29, mounted as above described, extend across the. widthof the machine and constitute means for wiping the entire width of thecellophane sheet, flm or web on both sides. It is essential that thewiping edge of the doctor blade 29 be even and kept in adjustment. Tothis end the edge of the blades is maintained and/or attained by themovement of the screws 42 above-described. In wiping both sides of acellophane film, Web or sheet, We have found that if the main blades 29are arranged at anangle to the passing film and in a staggeredpositionwe obtain highly satisfacto results. The staggering of the blades,

as-illustrated in Figure 3, permits the blades to overlap and, since theblades are ad'ustable, .the amount of overlapping is ad ustable.

This overlapping gives a good scrapin action and'permits the blades tobe spaced wider apartthan in the usual arrangement. The .wider spacingof the doctor blades is especially important since cellophane filmvaries in thickness. If the blades were spaced too close to each other,a thick portion of the film passing between the blades would "be damagedor torn.

The auxiliary doctor blades 30 (a pair disposed at each end of themachine) 'adjustably mounted as above. described, are adapted to engagethe zones adjacent the-longitudinal edges of the cellophane film.Accordingly, the doctor blades 30 are made-of such length as to onlywipe the desired area of the cellophane film, web or sheet. Varioulengths may be used. We have found that if the auxiliary blades 30 aretwelve inches in length when a film forty inches wide is treated,satisfactory results are obtained. The blades 30 may be staggered andoverlapped similar to the main blades 29, or the edges may bepositioned-in thesame plane.

The auxiliary doctor blades30 may be made of various materials. We'haveobtained satisfactory results when they were made of flexible materials,such as'spring brass with headed edge, leather, thin steel-and the like.

To thread the machine, it is necessary that the blades 29 and 30 beopened up or spread apart. For this purpose an externally geared handlemechanism 51 is provided. The handle mechanism 51 is mounted on pads 52and 53 of the casting 34 and, since both mechanisms are similar, onlyone will be dewhich is adapted to mesh with a gear 61 carried on anextension 62 of the trunnion 32 and supported in the journal 57. It isobvious that rotation of the handle 59 will rotate the trunnion 32whereby the blade holder will be moved and the blades separated. Inorder to indicate the amount of rotation, an indica' tor 63 or othermeans is fastened to the extension 62. The casing 54 may he graduatedwhereby the amount of rotation of the trunnion 32 may be instantlyrevealed by the indicator 63.

After the blades 29 and 30 have been adjusted and opened, and themachine threaded, the handle 59 is rotated, whereby the blades 29 and 30are closed. To insure that the blades return to their original adjustedositions, adjustable stops 64 are mounte on bosses 65 of the bladeholders. The stops comprise bolts 66 screwed in threaded holes 67in thebosses 65. Nuts or bolt-heads 68 on the extremity of bolts 66 areadapted to engage a stop-block 69 mounted on the pad 70 of the casting34 by means of a bolt 7 0 and positioning dowels. By means (Tf'a nut 71,or

other suitable means, the stop 64' may be, I after adjustment to anydesired position,

' film is caused to pass into a drier 6 located in locked.

After the blades 29 and 30 have been brought back to their original adjusted p'osition, means are provided to maintain the blades 29 and 30 inposition during the operation of the machine. The means for attainingthis result comprises hand clamp devices 72. Specifically, the handclamp 72 comprises clamping members 73 and 7 3' adapted to engage thetrunnion 32 and a screw 74 operated by rotation of the head 75, wherebythe clamping elements 73, 73 are tightened or loosened.

By means of ears 76 and bolts 77 and 77, respectively, the clamps aremounted on the end casting. 34.

As above mentioned, the entire wiping I mechanism 5 is slidably mountedwhereby it may be adjusted to any desired position in relation to thecoating bath. Various means may be used to attain this result. In thedrawings, we have shown one for efi'ecting this result. Extendingthrough the lower portion of the casting 34, is a channel 78 in which abar- 79 is positioned. One end 79' of the bar 79 is bent upwardly andhas a bolt 80 extending through a threaded hole 81 therein and through athreaded hole 82 in the asting 34. In its horizontal arm, the bar isformed with a slot 83 through which a bolt 88' connecting the casting 34to the frame extends. Rotation of the bolt 80 moves the entiremechanism. the limits of said movement being governed by the length ofslot 83. Suitable means may be mounted on the bolt 80 whereby rotationof'the screw is prevented when not desired.

In the arrangement of the doctor blades, above described, ithas beenfound that the tension on the film is of extreme importance and is oneof the factors which regulates the quantity of the coating which is lefton the film after passing through the blades. Low tensions result inconsiderably less friction on the film by theblades and consequentlyconsiderably more coating is left on the film than would result whenhigher tensions are employed. The thickness of. the coating may bevaried as much as 100% and over'by just varying the tension on the film.For this reason, it is necessary to employ a device which will maintainthe tension of the film through the doctor blades at some predeterminedadjustable tension. Various means may be employed We have found that bycontrolling the tension of the roll I from which the film is supplied,we can obtain a suitabletension through the doctor blades. We thereforeapply to the spindle on which the roll is carried any suitable brakingmeans applying a progressively increasing 'tension.

as the supply on the roll decreases. Since the specific details of thebrake means form no part of this invention, further description thereofis deemed unnecessary.

From the wlpmg mechanism 5 the coated close proximity to the wipingmechanism,

other solid ingredients of the coating composition, and is evidenced bythe hazy, translucent or opaque films. Paraffin or other 'wax possessesa definite and limited solubility in the coating compositions which weuse, said solubility depending primarily upon the temperature. At thetemperature approximately that of the melting point of the wax in thecomposition or higher, its solubility is many times greater than it isat lower temperatures. Accordingly, we maintain the temperature of thedrier at or above the melting point of the wax in the composition.

The drier 6 comprises a casing having heated coils 85 on both sidesthereof. Disposed at various points in the drier are doors 86 hinged tothe casing and provided with wire glass windows 87 whereby access to theinterior of the drier may be easily had and, due to the wire glasswindows 87, the interior of the drier may be at any time viewed. Thetemperature of the drier is preferably maintained in the vicinity or atthe entrance of the film at 80. C. to (1., and the remainder of thedrier is maintainedat such a temperature that the paraflin or other waxwill not be precipitated-out. The upper sections of the drier aremaintained at; a temperature of not lower than 60 C. to 65 C.

duced through pipes, the openings of which are covered with canvas,produces satisfactory results. W e have also found that this result. Wehave found that steam introsatisfactory results are obtained if thehumidification is carried out at a temperature higher than roomtemperature and preferably above 40 C. and around 50 C. to 60 C.

- To attain this esult, the humidifying. chamher is provided withheating coils. The humidifier is also provided with doors having windowssimilar to the drier 6. The drier 6 and the humidifier 7 may be formedseparately and disposed adjacent each other. However, they may be.formed from a single casing having a partition therein and sepa- Iratingthe'two-zones, as illustrated in Figure 1.

In the humidifier 7 the flexibilit and pliability ofthe coated film isrestored During.

the process when the film is subjected to a temperature greater than thecritical temperature corresponding closely to the melt able film. Duringthis final step substantially all the solvent is eliminated and thefilmrendered odorless.

Whenthe film finally issues from the warm humidifying chamber and intothe air, it

I tended to cover the temperature as set forth is cooled in any suitablemanner as by ermitting the film to cool itself or by emp oying anysuitable means for cooling it, whereby its temperature drops and themoistureproof properties of-the coating are restored. Upon cooling, thecoating seals the base material and the moisture which the base haspicked up.

From the humidifier the coated film passes through the air and is woundon a roll.

In the above method the material treated is described as a continuousfilm or web. The invention is not limited thereto since it -is obviousthat sheets-of various sizes may be treated by the herein-describedmethod.

. In the claims the expression a temperature approximately that of themelting point of said wax is used. This expression is inin thedescription, viz.,- a temperature approximately the same or higher thanthe melting point of the wax in the composition.

Throughout the description the term wax is employed. .It is to beunderstood that this terminology is intended to cover'one or more waxesemployed alone or in combination with Wax-like bodies.

In the claims the term solvent is intended to cover one or more solventsfor cellulose derivatives used either alone or in combination with oneor more diluents to form solvent mixtures.

Though the hereinbefore description relates specifically to themoistureproofing of cellophane, it is obvious that it is not restrictedthereto, since the essential features of this invention may be employedin coating 'jecting a sheet or film of regenerated cellunumerous baseswith various compositions.

Since it is obvious that various modifications may be made in theapparatus abovedescribed, we do not intend to limit ourselves to theexact details above-described except as .70 defined in the followingclaims.

We claim: 1'. A method of coating which comprises I subjectinga base toa humidifying treatment, applying a moistureproofing composition 7comprising a cellulose derivative, a wax and a solvent to said base,raising the temperature of said composition on said base as re. idly aspossible to approximately the me tin point of the wax, andevaporatingthe so vent at said temperature.

2. A method of coatin which comprises subjecting a base to a humidifyingtreatment, applying a moistureproofing composition comprising acellulose derivative, a wax and 35 a solvent to said base, raisin thetemperature of said composition on sai base as ra idly as possibletoapproximately theme ting point of the wax, evaporating the solvent atsaid temperature, and subjecting the coated material to a humidifyingtreatment.

3. A method of coating which comprises subjecting a base to ahumidifying treatment, applying a' moistureproofing compositioncomprising a cellulose derivative, a wax and. a solvent, and evaporatingsaidsolvent at a temperature approximately the melting point of the wax.v Y

4. A method of coating which comprises subjecting a base to ahumidifying treatment, applying a moistureproofing compositioncomprising a cellulose derivative, a wax and a solvent, evaporating saidsolvent at a temperature approximately the meltin point of the wax, andsubjecting the coated material to a'humidifying treatment.

5. A method of preparin a moistureproof transparent material whiccomprises subj ecting a sheet or film of regenerated cellulose to ahumidifying treatment, applying a mois- .tureproofing compositioncomprising a cellulose derivative, a wax and a solvent to saidregenerated cellulose, raising the temperature of said composition onsaid sheet as rapidly as possible to approximately the melting point ofthe wax, and evaporating the solvent at said temperature.

6. A method of preparing a moistureproof transparent material whichcomprises sub- .1

. 20 lose to a humidifying treatment, applying a moistureproofingcomposition comprising a cellulose derivative, a wax and a solvent tosaid regenerated cellulose, raising the temperature of 'said compositionon said sheet as rapidly as possible to approximately the melting pointof the wax, evaporating the solvent at said temperature, and subjectinthe coatedregenerated cellulose to a humidiging treatment. 130

transparent material whic 7. A method of preparin a moistureproofcomprises subjecting a sheet or film of regenerated cellulose to ahumidifying treatment, applying thereto a moistureproofing compositioncomprising a cellulose derivative, a waxand a solvent, and evap'oratmgsaid solvent at a temperature approximately that of the melting point ofsaid wax.

8. A method of preparin a moistureproof transparent material whicComprises sub-' jecting a sheet or film of regenerated cellulose to ahumidifying treatment, applying thereto a moistureproofing compositioncomprising a cellulose derivative, a wax and a solvent, evaporating saidsolvent at a temperature approximately that of the melting point :ofsaid wax, and subjecting said coated regenerated cellulose to ahumidifying treatment,

9. A method of preparing a moistureproof transparent material a sheet orfilm of re,

generated cellulose, which comprises subjecting said regeneratedcellulose to a humiditying treatment, applying a moistureproofing Icomposition comprising a cellulose derivative, a wax and a solvent,evaporating said 7 solvent at a temperature approximately that that ofthe melting point of said wax, subjectin said coatedregeneratedcellulose to a humi ifying treatment, and cooling said coatedregenerated cellulose.

11. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying amoistureproofing composition to a sheet or film of regenerated cellulosehaving beads on its longitudinal edges, wiping the zones adjacent thebeads of said sheet or film to remove a'portion of the excess of saidcomposition, and then wiping the entire surface of said sheet or film toremove the excess of said composition.

12. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying amoisturepi'oofing composition to a sheet or film of regeneratedcellulose having beads on its longitudinal edges, wiping the zonesadjacent the beads of said sheet or film to remove a portion of theexcess of said composition wiping the entire surface of said sheet orfilm to remove the excess of said composition, and maintaining saidsheet or film at a substantially uniform tension at least 'duringthesecond wiping operation.

'13.-A method of preparing a moisture' stantially uniform coated surfacewhich comprises applying a moistureproofing composition to a sheet orfilm of regenerated cellulose having beads on its longitudinal edges,Wiping the zones adjacent the beads to remove a portion of the excess ofsaid composition, wiping the entire Width. to remove the excess of saidcomposition, and drying said treated sheet or film.

15. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying a.moistureproofing composition to a sheet or film of regeneratedcellulose having beads on its longitudinal edges, wiping the zonesadjacent the beads to remove a portion of the excess of saidcomposition, wiping the entire Width to remove the excess of saidcomposition,drying and subjecting said coated sheet or film to ahumidifying treatment.

16. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying amoistureproofing composition including a volatile solvent to a sheet orfilm of regenerated cellulose having beads on its longitudinal edges,removing the excess of said composition first at the zones adjacent thebeads and then from the'entire width of the sheet or film being treated,evaporating the solvent, and humidifying said coated regeneratedcellulose.

17. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying to a sheetor film of regenerated cellulose having beads on its longitudinal edgesa moistureproofing composition includin a volatile solvent, removing theexcess 0 said composition first from the zones adjacent the beadsthereof and then from the entire width of the sheet or film beingtreated, evaporating said solvent, and deodorizing said coatedregenerated cellulose.

18. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comprises applying to a sheetor film of regenersecond wiping operation.

' ated cellulose having beads 611 its longitudinal edges amoist-ureproofing com osition including avvolatile solvent,remov1ng theexcess "of said composition first from the zones adjacent the beadsthereof and then from the entire width of the sheet or film beingtreated, evaporating said solvent, and deodorizing said coatedregenerated cellulose, said sheet or film being maintained at asubstantially uniform tension at least during the 19. A method ofpreparing a moistureproof transparent material having a substantiallyuniform coated surface which comprises applying to a sheet or film ofregenerated cellulose having beads, on its longitudina-l edges amoistureproofing composition. including a volatile solvent and a wax,removing the excess of said composition first from the zones adjacentthe beads thereof and then from the entire width of the sheet or film,andevaporat-ing said solvent at, a temperature approximately the same asthe melting point of said iwax.

20-. A 'inethod of preparing a moistureproof transparent material havinga sub.-

stantially uniform coated surface which comprises applying to a sheet orfilm of regener- "ated cellulose having beads on its longitudinal edgesa n'ioistureproofing composition 1neluding a volatile solvent and a wax,removing the excess of said composition first from the zones adjacentthe beads thereof and then from the entire Width of said sheet or film,

evaporating said solvent at a temperature approximately the same as themelting point 'or' said wax, and'subjectin-g said, coated reprisesapplying to a sheet or film of regenergenerated'cellulose to ahumidifying treatment.

21. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which comated cellulose havingbeads on its longitudinal edges a moistureproofing composition includinga volatile solvent and a wax, removing the excess composition first fromthe zones adjacent the beads thereof and then from the entire Width ofsaid sheet or film,

evaporating said solvent at a temperature approximately the same as themelting point of sa1d wax, and deodorizing said coated rcgeneratedcellulose.

' '22. A method of preparing a moistureproof transparent material havinga substantially uniform coated surface which coma prises applying to asheet or film of regenerated cellulose having beads 'on its longitudinaledges a moistureproofing composition including a volatile solventand awax, re-

moving'the excess of said composition first from the zones adjacent thebeads thereof and then from the entire width of said sheet or film, andevaporating said solvent at a temperature approximatelythe same as the.

--wiping operation.

25. A method of preparing a moistureproof transparentmaterial having asubstan melting point of the wax, said regenerated cellulose beingmaintained ata substantially uniform tenslon-at least during the secondwiping operation.

23; A method of preparing a proof transparent material having asubstantially uniform coated surface which comprises applying to a sheetor film of regenez; ated cellulose having beads on its longitudinaledges a moistureproofing composition including a volatile solvent and awax, r'emoving the excess of said composition first from-the zonesadjacentthe beads thereof and then from the entire width of said sheetor film, evaporating said solvent at a tem-' perature approximately thesame as the melting point of the Wax, and subjectin said coatedregenerated cellulose to a humidifying treatment, said rcgenergtedcellulose being mamtamed at a substantially uniform tension at leastduring the second wiping operation.

24. A method of preparing a moistureproof transparent material having asubstantially uniform coated surface which -com'- moistureprisesapplying to a sheet or film of regenerated cellulose having beads on itslongitu dinal edges a moistureproofing composition including a volatllesolvent and a wax, re-

-moving the exqess of said composition first from the zones adjacent thebeads thereof and then from the entire width of said sheet or film,evaporating said solvent at attemperature approximately the same as themelt: ing point of the wax, and deodorizing said coated regeneratedcellulose, said regenerated cellulose bein maintained at asubstantially" uniform tension at least during the second tially uniformcoated surface which comprises subjecting a sheet or film of regeneratedcellulose having beads 011 its longitudinal edges to a humidifyingatmosphere,

applying a moisture proofing composition thereto, wiping the zonesadjacent thebeads to remove a portion of the excess of said com-'position, wiping the entire width to remove the excess of'saidcomposition, and drying said treated sheet or film.

26. A method of preparing, a moistu-zeproof transparent material havinga substantially uniform coated surface which comsheet orfilm to ahumididinal edges to .Sll)

roof transparent material having a substandinal edges ,t'o-a humidifyingatmosp ere,

thereto a moistureproofing compo removing a l in si tibfi .inaluding avolatile solvent the excess of said composition ti zones adjacent thebeadsand then from the entire width of the sheet or film beingtreated,evaporating the solvent, and humidifying said coated regeneratedcellulose. I j

' 28. ,A method of preparing a moistureproof transparent material havinga substantially uniform coated surface which com prises subjecting asheet or film of regenerated cellulose having beads on l-tS longituahumidifying atmosphere, applying thereto a moistureproofing compositionincluding a volatile solvent, removing the excess of said composltionfirst from the zones adjacent the beads and then from the entire widthof the sheet or film being treated, evaporating the solvent, anddeodorizing the coated regenerated cellulose.

29. A method of preparing a molstureproof transparent material having asubstantially uniform coated surface which comprises subjecting asheetor film of regenerated cellulose having beads on its longltudmaledges to a humidifying atmosphere, applying'thereto a moistureproofingcomposition including a volatile solvent, removing the excess of saidcomposition first from the zones ad acent the beads and then from theentire width of the sheet or film being treated, evaporating thesolvent, and deodorizing said coated regenerated cellulose, said sheetor film being maintained at a substantially uniform tension at leastduring the second wiping operation.

30. A method of preparaing a moistureproof transparent material having asubstantially uniform coated surface which comprises subjecting a sheetor film of regenerated cellulose having beads on its longitudinal edgesto a humidifying atmosphere, applying thereto a moistureproofingcomposition including a volatile solvent and a wax, removing the excessof said composition first from the zones adjacent the beads and thenfrom the entire width of said sheet or film, and evaporating saidsolvent at a temperature approximately the same as the melting point ofsaid wax. 7

31. A method of preparing moistureproof transparent material having asubstantially uniform coated surface which comprises sub- "jecting asheet or film of regeneratedcellulose having beads on its longitudinaledges to a humidifying atmosphere, applying thereto a moistureproofingcomposition ineluding a volatile solvent and a wax, removing theexoess'of said composition first from the zones adjacent the beads andthen from rst at the the entire width of said sheet or film, evaporatingsaid solvent at a temperaure approximately the same as the meltmg pointof said wax, and subjecting said coated regenerated cellulose to ahumidifyin treatment.

32. A method of preparlng a moistureproof transparent-material having asubstantially uniform coated surface which comprises subjecting a sheetor film of regenerated cellulose having beads on its longitudinal edgesto a humidifying atmosphere, applying there to a moistureproofingcomposition including a volatile solvent and a wax, removing the excessof said composition first from the zones adjacent the beads and thenfrom the entire width of said sheet or film, evaporating said solvent ata temperature approximately the sameas the melting point of said wax,and deodorizing said coated regenerated cellulose.

33. A method of preparinga moistureproof transparent material having asubstantially uniform coated surface which comprises subjecting a sheetor film of regenerated cellulose having beads on its longitudinal edgesto a humidifying atmosphere, applying thereto a moistureproofingcomposition including a volatile solvent and a wax, removing the excessof said composition first from the zones adjacent the beads and thenfrom the entire width of said sheet or film, and evaporating saidsolvent at a temperature approximately the same as the melting point ofsaid wax, said regenerated cellulose being mainexcess of saidcomposition first from the zones adj acent the beads and then from theentire width of said sheet or film, evaporating said solvent at atemperature approximately the same as the melting point of said wax, andsubjecting said coated regenerated cellulose to a humidifying treatment,said regenerated cellulose being maintained at a substantially uniformtension at least during the second wiping operation. I

- 35. A method of preparing a moistureproof transparent material havinga substantially uniform coated surface which comprises subjecting asheet or film of regenerated cellulose having beads on its longitudinaledges to a humidifying atmosphere, applying thereto a moistureproofingcomposition including a volatile solvent and a wax, removing the excessof said composition first from the zones adjacent the beads and thenfrom the entire width of said sheet or film,

evaporating said solvent at a temperature approximately the same as themelting point of said wax, and deodorizing said coated regeneratedcellulose, said regenerated cellu-- lose being maintained at asubstantially uniform tension at least during the second Wipingoperation. v

36. A method of preparing a material having a substantially uniformcoated surface which comprises applying a coating composition to a sheetor film having beads on its longitudinal edges, Wiping the zonesadjacent the beads of the said sheet or film to remove a portion of theexcess of said composition and then Wiping the entire surface of saidsheet or film to remove the excess of said composition.

37. A method of preparing a material having a substantially uniformcoated surface which comprises applying a coating composition to a sheetor film having beads on its I longitudinal edges, wiping the zonesadjacent the beads of said sheet or film to remove a portion of theexcess of said composition, wiping the entire surface of said sheet orfilm to remove the excess of said composition and maintaining said sheetor film at a substantially uniform tension at least during the secondwiping operation.

' In testimony whereof, we have afixed our signatures to thisspecification.

. LIAM H. CHARGH. NORMAN A. CRAIGUE.

